Carbocyanine dyes and process of making same



Patented Jan. 5, 1926.

um'rnn STATES.

PATENT OFFICE.

GUM O. GUTEKUNST, OF BOOK ESTER, NEW YORK, ASSIGN'OB TO KODAK COMPANY, OI' ROO'HE8'1'ER, NEW YORK, A CORPORATION 01 NEW YORK.

CABBOGYANINB DYES AND PROCESS OF MAKING sum.

Io Drawing.

To all whom it may concern:

Be it known that I, Gunner O. Gurn- KUNST. a citizen of the United States of America, residing at Rochester, in the 6 county of Monroe and State of New York, have invented certain new and useful Improvements in Carbocyanine Dyes and Processes of Making Same, of which the following is a full, clear, and exact specification.

This invention relates to carbocyanine dyesefl'ective for red and infra-red sensitization of photogra hic emulsions.

I have discovere that dyes of this type may be obtained by the action of a stro base upon a beta-naphtho-quinaldine alky halide in the resence of a suitable condensing agent. ore specifically the above named intermediate is condensed upon itself, either alone or in the presence of certain other compounds such as a quinoline alkyl-halide or a phenanthroline alkylhalirle, when in solution with a strong base or alkali, such as alcoholic potash, sodium methylate or sodium ethylate, or an'a noous solution of sodium or potassium ydroxide, and also of a suitable condensing agent such as a trihalogen methane or formaldehyde.

When a trihalog en methane is used the intermediate alone is used; but when formaldehyde is the condensing agent .the presence of one of "the additional compounds is particularly useful, though it a' parently does not enter into the finished ye. The

:5 use of a trihalogen methane and particularly iodoform is preferred as theyield is very much greater and the reaction much more certain. I v

The following example will serve to illus- 4o trate the preferred procedure: A solution of 5 rams of beta-naphtho-quinaldine ethiodi e in 500 cc. of boiling 95% ethyl alcohol Application fled September, 1921. Serial No. 504,907.

is treated with a mixture of 15 cc. alcoholic potash and 4 gramsof iodoform dissolved in cc. of 95% ethyl alcohol. A blue solution forms at once and small green needle crystals immediately separate. These are recrystallized from methyl or ethyl alcohol.- It is solid at ordinary temperatures.

This dye of the carbocyanme series is particularly useful for sensitizing photographic emulsions for-red and infra-red. The maximum sensitivity is at about 700p. but its sensitizing eflect extends to a useiiil degree beyond 740ml. 7

Having thus described my invention, wha I claim as new and desire to secure by Letters Patent is:

1. A dye of the carbocyanine t produced'by the condensation on itse fof a naphtho-quinaldine al lhalide.

2. A dye 'of the car cyanine ty e produced by the condensation on itse f of a beta-naphtho-quina'ldine alkylhalide in solu-. tion with a strong base and a condensing agent.

3. A dye produced by the condensation on itself of beta-naphtho-quinaldine ethiodide. in alcoholic solution with an alkali and iodoform. 1

4. The process of producing a dye of the' carbocyanine type that comprises con-v densin beta-naphtho-quinaldine ethiodide on itse f in the presence of an alkali and of a trihalogen methane.

5. The process of producing a dye efiective. for infra-red photographic sensitization that comprises treating beta-naphtha quinaldine ethiodide with alcoholic potash in the presence of iodoform.

Signed at Rochester, New York, this 24th dayof September, 192

GURNEY O. GUTEKUNST. 

